Traditionally mechanical fasteners are used to mechanically link two or more articles together. Mechanical fasteners come in various shapes and sizes and they have a variety of constructs. The type of construct depends in part on the environmental conditions in which the fastener system must operate. Some may operate in high stress, shear, compression or tension conditions, and some may operate in high temperature, low temperature, or just ambient temperature conditions. Thus, depending on the circumstances, the design of fastener system may be changed.
One style of mechanical fastener includes rivets. A problem with rivet type fasteners is that rivet heads have been known to be liberated into engines, causing damage. This is because the rivet construct may not have tightly controlled material strength and structural integrity. This in part may be because the quality of the rivet is subject to the quality of work of the operator who forms the rivet. If a rivet has been unknowingly overworked, it may not have the fatigue life that was assumed. Thus, rivet constructs are not dependable or desirable to use in engines, or other locations or machinery, where potentially causing damage to the machinery is an issue.
It would be helpful to provide an improved mechanical joint. Such a joint could be formed by a welder who melts a retention pin only into a pocket. The welder can watch the molten metal flow into the pocket to know that he has finished the forming operation. The fatigue properties of the melt-formed pin may be the same as the solution heat treated form of the pin material.